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Home >> Nissan-Datsun >> 2019 >> Altima SL, FWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (Pr25DD) (1 Of 3) >> System Description >> Diagnosis System (ECM) >> Diagnosis Description >> On Board Diagnosis Function >> PR25DD engine
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PR25DD engine

ON BOARD DIAGNOSIS ITEM 

The on board diagnostic system has the following functions.

Diagnostic test mode

Function

Bulb check

MIL can be checked.

SRT status

ECM can read if SRT codes are set.

Malfunction warning

If ECM detects a malfunction, it illuminates or blinks MIL to inform the driver that a malfunction has been detected.

Accelerator pedal released position learning

ECM can learn the accelerator pedal released position. Refer to Work Procedure .

Throttle valve closed position learning

ECM can learn the throttle valve closed position. Refer to Work Procedure .

BULB CHECK MODE 

Description 

This function allows damage inspection in the MIL bulb (blown, open circuit, etc.).

Operation Procedure 

  1. Turn ignition switch ON.
  2. The MIL on the instrument panel should stay ON.

    If it remains OFF, check MIL circuit. Refer to Malfunction Indicator Lamp (MIL) .

SRT STATUS MODE 

Description 

This function allows to read if ECM has completed the self-diagnoses of major emission control systems and components. For SRT, Refer to System Readiness Test (SRT) Code .

Operation Procedure 

  1. Turn ignition switch ON and wait 20 seconds.
  2. SRT status is indicated as shown blow.
    • ECM continues to illuminate MIL if all SRT codes are set.
    • ECM blinks MIL for about 10 seconds if all SRT codes are not set.
    G05868475Courtesy of NISSAN NORTH AMERICA, INC.

MALFUNCTION WARNING MODE 

Description 

In this function ECM turns on or blinks MIL when it detects a malfunction in the emission control system components and/or the powertrain control components (which affect vehicle emissions) to inform the driver that a malfunction has been detected.

Operation Procedure 

  1. Turn ignition switch ON.
  2. Check that MIL illuminates.

    If it remains OFF, check MIL circuit. Refer to Malfunction Indicator Lamp (MIL) .

  3. Start engine and let it idle.
    • For two trip detection logic diagnoses, ECM turns on MIL when it detects the same malfunction twice in the two consecutive driving cycles.
    • For 1st trip detection logic diagnoses, ECM turns on MIL when it detects a malfunction in one driving cycle.
    • ECM blinks MIL when it detects a malfunction that may damage the three way catalyst (misfire).
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